Initiation of controlled radical polymerization from lactide monomer

Abstract

A lactide-functionalized polymer is synthesized by polymerizing a monomer capable of undergoing radical polymerization (e.g., styrenic, vinylic, acrylic, etc.) using a brominated lactide initiator via atom transfer radical polymerization (ATRP). In some embodiments of the present invention, the brominated lactide initiator is 3-bromo-3,6-dimethyl-1,4-dioxane-2,5-dione prepared by reacting lactide with N-bromosuccinimide in the presence of benzoyl peroxide.

What is claimed is: 
     
       1. A method for synthesizing a lactide-functionalized polymer, comprising:
 polymerizing a monomer using a brominated lactide initiator via atom transfer radical polymerization (ATRP), wherein the brominated lactide initiator is 3-bromo-3,6-dimethyl-1,4-dioxane-2,5-dione and wherein the monomer is represented by the following formula: 
 
       
         
           
           
               
               
           
         
         wherein R is a hydrogen atom or a methyl group, and wherein R′ is a phenyl group or C(O)OR″, wherein R″ is an alkyl group having one or more carbon atoms. 
       
     
     
       2. The method as recited in  claim 1 , wherein the monomer is selected from the group consisting of styrene, butyl acrylate, methyl acrylate, 2-ethylhexyl acrylate, ethyl acrylate, 2-ethylhexl methacrylate, ethyl methacrylate, butyl methacrylate, and combinations thereof. 
     
     
       3. The method as recited in  claim 1 , wherein the monomer is styrene. 
     
     
       4. The method as recited in  claim 1 , wherein the monomer is butyl acrylate. 
     
     
       5. The method as recited in  claim 1 , wherein the step of polymerizing a monomer using the brominated lactide initiator via atom transfer radical polymerization (ATRP) comprises the step of preparing a catalytic copper/ligand complex comprising a copper(I) complex and a ligand with a slight excess of copper prior to adding the brominated lactide initiator to the copper/ligand complex. 
     
     
       6. The method as recited in  claim 1 , further comprising the step of:
 reacting lactide with N-bromosuccinimide in the presence of benzoyl peroxide to prepare the bromated lactide initiator. 
 
     
     
       7. The method as recited in  claim 1 , further comprising the step of:
 reacting lactide with bromine (Br 2 ) in the presence of benzoyl peroxide to prepare the bromated lactide initiator. 
 
     
     
       8. A method for synthesizing a lactide-functionalized polymer, comprising:
 preparing a brominated lactide initiator, wherein the brominated lactide initiator is 3-bromo-3,6-dimethyl-1,4-dioxane-2,5-dione; 
 polymerizing a monomer using the brominated lactide initiator via atom transfer radical polymerization (ATRP), wherein the monomer is represented by the following formula: 
 
       
         
           
           
               
               
           
         
         wherein R is a hydrogen atom or a methyl group, and wherein R′ is a phenyl group or C(O)OR″, wherein R″ is an alkyl group having one or more carbon atoms. 
       
     
     
       9. The method as recited in  claim 8 , wherein the monomer is selected from the group consisting of styrene, butyl acrylate, methyl acrylate, 2-ethylhexyl acrylate, ethyl acrylate, 2-ethylhexl methacrylate, ethyl methacrylate, butyl methacrylate, and combinations thereof. 
     
     
       10. The method as recited in  claim 8 , wherein the monomer is styrene. 
     
     
       11. The method as recited in  claim 8 , wherein the monomer is butyl acrylate. 
     
     
       12. The method as recited in  claim 8 , wherein the step of polymerizing a monomer using the brominated lactide initiator via atom transfer radical polymerization (ATRP) comprises the step of preparing a catalytic copper/ligand complex comprising a copper(I) complex and a ligand with a slight excess of copper prior to adding the brominated lactide initiator to the copper/ligand complex. 
     
     
       13. The method as recited in  claim 8 , wherein the step of preparing a brominated lactide initiator comprises the step of reacting lactide with N-bromosuccinimide in the presence of benzoyl peroxide. 
     
     
       14. The method as recited in  claim 8 , wherein the step of preparing a brominated lactide initiator comprises the step of reacting lactide with bromine (Br 2 ) in the presence of benzoyl peroxide.